Liquid storage container with insulated casing enclosing emergency relief vent

Abstract

A volatile liquid storage facility having an inner tank containing a fuel storage chamber for retaining volatile fuel. An outer tank is formed surrounding and arranged concentric with the inner storage tank. The inner and outer tanks are spaced apart from one another by a predefined spacing which is filled with a fire retardant insulative material. The insulative material resists transfer of thermal energy between the inner and outer tanks. A vent is provided in communicating relation with the fuel chamber and projected outward therefrom. The vent passes through the insulative layer and through the outer tank to allow vapor to escape from the fuel chamber when a pressure therein exceeds a desired threshold level. An insulative shell is mounted to the exterior of the outer tank to enclose the vent in order to substantially isolate the vent from external environmental heat.

What is claimed is: 
     
       1. A liquid storage facility, comprising: an inner tank having a chamber therein for storing a liquid;   an outer tank surrounding and arranged concentric with said inner storage tank, said inner and outer tanks being spaced apart from one another by a predefined spacer gap;   insulation material disposed in said spacer gap for resisting transfer of thermal energy between said inner and outer tanks;   vent means communicating with said chamber and extending outward from said inner tank and through said insulation material and outer tank to an exterior environment, for allowing vapor to escape from said chamber when a pressure therein exceeds a desired threshold; and   insulation means, mounted to an exterior of said outer tank and enclosing said vent means for substantially isolating said vent means from external environmental heat to which said outer tank is exposed.   
     
     
       2. A liquid storage facility according to claim 1, wherein said insulation means includes a casing with a top, the casing surrounding a portion of said vent means projecting outward beyond said outer tank, and a top plate mounted upon the top of said casing to form an insulated venting chamber. 
     
     
       3. A liquid storage facility according to claim 1, wherein said insulation means includes a peripheral layer of insulation surrounding an exterior portion of said vent means extending beyond an exterior of said outer tank. 
     
     
       4. A liquid storage facility according to claim 1, wherein said vent means includes a tubular pipe secured to said inner tank, said tubular pipe having a passage therethrough communicating with said chamber and wherein said insulation means includes a layer of insulation received within and partially filling said passage, said insulation layer resisting transfer through said passage of thermal energy between the external environment and said chamber. 
     
     
       5. A liquid storage facility according to claim 1, wherein said insulation means includes a tubular casing with a top plate mounted thereon and having a venting port therebetween, said casing and top plate surrounding a discharge port of said vent means to resist transfer of external heat through said discharge port and a wall of said vent means into said fuel chamber. 
     
     
       6. A volatile fluid storage container, comprising: inner and outer containers arranged concentrically with one another, said inner container having a fluid chamber for storing volatile fluid;   a safety relief vent projecting through said inner and outer containers to form an emergency relief passage from said fluid chamber to an external environment; and   an insulated shell enclosing a portion of said relief vent extending outward beyond said outer container, for preventing external heat from migrating inward through a wall of said vent and through said relief passage into said fluid chamber.   
     
     
       7. A volatile fluid storage container according to claim 6, further comprising an insulative layer of fire retardant material disposed between said inner and outer containers. 
     
     
       8. A volatile fluid storage container according to claim 6, wherein said insulated shell includes a casing with a top, the casing surrounding a portion of said relief vent projecting outward beyond said outer container, and a top plate mounted upon the top of said casing to form an insulated venting chamber. 
     
     
       9. A volatile fluid storage container according to claim 6, wherein said insulated shell includes a peripheral layer of insulation surrounding an exterior portion of said relief vent which extends beyond an exterior of said outer container. 
     
     
       10. A volatile fluid storage container according to claim 6, wherein said relief vent includes a tubular pipe secured to said inner container, said tubular pipe having a passage therethrough communicating with said fluid chamber and wherein said insulated shell includes a layer of insulation received within and partially filling said passage, said insulation layer resisting transfer through said passage of thermal energy between the external environment and said chamber. 
     
     
       11. A volatile fluid storage container according to claim 6, wherein said insulated shell includes a tubular casing with a top plate mounted thereon and having a venting port therebetween, said casing and top plate surrounding a discharge port of said relief vent to resist transfer of external heat through said discharge port and a wall of said relief vent means into said fluid chamber. 
     
     
       12. A method of forming a liquid storage facility, comprising the steps of: forming a double walled storage tank with inner and outer walls for storing liquid in the inner wall;   filling an interstitial space between the inner and outer walls with a first layer of insulation to thermally isolate the inner wall from an exterior environment;   providing a relief vent between extending through said outer wall to discharge pressurized vapor, said vent extending through said layer of insulation; and   thermally isolating said relief vent with a second layer of insulation, at least a portion of which is located outside said outer wall.   
     
     
       13. A method according to claim 12, wherein a portion of the relief vent extends beyond the exterior wall and further comprising: surrounding a portion of said relief vent extending beyond said exterior wall with insulation.   
     
     
       14. A method according to claim 12, further comprising: surrounding a portion of said relief vent extending beyond said exterior wall with insulation.   
     
     
       15. A method according to claim 12, further comprising: forming a shell about said relief vent and filling said shell with insulation.